[thankfulguy]

1. Install Spybot S&D in your system and scan for all spywares installed in that PC. Remove all of them.
2. Remember to uncheck "Remember my Password" option before log-in to your account.
3. Create a password which is easy to remember for you but difficult to guess for others. But it should not be a word to be found in dictionary. You may follow the pattern advised by 'slavezero' or 'The Doctor'. Never use your birthday or lover's name or some other information as password which is known to others.
4. Change your password frequently from a computer thoroughly checked for viruses and spywares.